Natural food sources that contain high amounts of glycine include; fish, meats, beans, and dairy products. Serving sizes below are based upon 100 grams of a given food source and are expressed in milligrams, representing the amount of glycine contained. [1]

Glycine is a primary component in many of the body’s intricate internal processes. Among its most important duties include; the biosynthesis of nucleic acids, bile acids, and porphyrins. Porphyrins are pigments found in both plants and animals, and are important ingredients in hemoglobin (carries oxygen in the blood). Glycine is also directly responsible for the development of DNA and RNA, both of which represent genetic coding on various biological levels.

Skin proteins, collagen, and phospholipids (which are responsible for the creation of cell membranes) are made by this amino acid. Glycine is also directly responsible for specific biochemical reactions within our skeletal muscles that assist in the production of usable energy. “Having too much of this amino acid in your body can cause fatigue, but having the proper amount produces more energy.” [2]

In association with muscular activities, glycine prevents muscular degeneration by supplying additional creatine throughout the body. This may prove especially important in one’s ability to use glycine for the reparation of damaged tissues throughout the body, and promoting sound, overall health.

Clinically, glycine has shown promise in maintaining the overall health of the prostate gland in men. Like glutamic acid, glycine is found abundantly in prostate fluid.. In combination with the amino acids alanine and glutamic acid, glycine has been used used in various clincial applications to reduce the symptoms associated with benign prostatic hyperplasia, or BPH. [3, 4]

Neurological benefits may also be derived from proper dietary supplementation of glycine. This particular amino acid may prevent hyperactivity in the brain, while also being effective at limiting (perhaps even preventing) epileptic seizures. Scientists speculate that this is the result of glycine’s ability to enhance the activity of certain chemical messengers in the brain (i.e. neurotransmitters). Glycine may prove effective in conditions associated with memory and cognitive behavior as well. [5]

Because glycine is considered a nonessential amino acid, a Recommended Daily Allowance has not been established. [6] However, the U.S. National Academy of Sciences recommends that healthy people achieve .36 grams of highly bioavailable protein for each pound of bodyweight - equaling 0.8 grams of protein, per kilogram of bodyweight.

Glycine Deficiencies

Very few people are glycine deficient. Because the body may produce its own supply of glycine in times of need or stress, deficiency is often seen in persons neglecting proteins in their diet.

Glycine Toxicities

There has been no clear scientific data supporting a definite toxicity from excessive consumption of glycine. However, animal models suggest that there is potential for the onset of toxicity when taking mega doses of this amino; which may result in neurotoxicity and glycine-induced hyponatremia. [7] It is also recommended that persons suffering form kidney or liver impairments not consume high levels on amino acids.